CN218851353U

CN218851353U - Under-actuated manipulator device

Info

Publication number: CN218851353U
Application number: CN202221047647.6U
Authority: CN
Inventors: 肖英奎; 刘星; 王乾赫; 何涛; 李捷; 杨俊松; 苏建彰; 陈燕红
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2022-05-05
Filing date: 2022-05-05
Publication date: 2023-04-14
Anticipated expiration: 2032-05-05

Abstract

The utility model belongs to the technical field of the robot, specific under-actuated manipulator device that says so. The palm-type hydraulic press comprises a palm, two fingers, a transmission rod, a central sleeve, a transmission rod assembly, an intermediate shaft and a hydraulic cylinder; a piston at the output end of the hydraulic cylinder is fixedly connected with one end of the transmission rod assembly; the other end of the transmission rod assembly is fixedly connected with the central sleeve; the central sleeve is sleeved on the central shaft; the upper end of the central shaft is fixedly connected with the palm; the palm is fixedly connected with the hydraulic cylinder through a connecting piece; one end of the transmission rod is hinged with the central sleeve, and the other end of the transmission rod is hinged with the sliding block; the sliding block is fixedly connected with the lower ends of the two sections of fingers; the two fingers slide in a disc groove on the palm; the two fingers grab and wrap different crops. The utility model discloses the drive finger moves to the fruit position, and then snatchs the fruit according to the crooked degree of fruit shape control manipulator, has solved the big problem of current manipulator device energy consumption.

Description

Under-actuated manipulator device

Technical Field

The utility model belongs to the technical field of the robot, specific under-actuated manipulator device that says so.

Background

Currently, the mechanization degree of Chinese picking operation is still low, and economic benefit and market benefit are lost due to a plurality of problems caused by untimely picking. Achieving mechanization in this area is therefore a problem that is urgently sought to be solved today. Meanwhile, in the design process of various manipulators, the reduction of corresponding energy consumption is also an important consideration target. The existing mechanical arm has many driving units, large energy consumption, complex structure and high production cost. In addition, many manipulators can only pick a single fruit type, and are difficult to apply to the actual manipulator picking process.

Disclosure of Invention

The utility model provides an under-actuated mechanical hand device, drive finger among the device moves to the fruit position, and then snatchs the fruit according to the crooked degree of fruit shape control manipulator, has solved the big problem of current mechanical hand device energy consumption.

The technical scheme of the utility model is explained as follows with the attached drawings:

an under-actuated mechanical hand device comprises a palm 4, two fingers, a transmission rod 6, a central sleeve 8, a transmission rod assembly 9, a central shaft 10 and a hydraulic cylinder 12; a piston 11 at the output end 16 of the hydraulic cylinder 12 is fixedly connected with one end of the transmission rod assembly 9; the other end of the transmission rod assembly 9 is fixedly connected with the central sleeve 8; the central sleeve 8 is sleeved on the central shaft 10; the upper end of the central shaft is fixedly connected with the palm 4; the palm 4 is fixedly connected with the hydraulic cylinder 12 through a connecting piece; one end of the transmission rod 6 is hinged with the central sleeve 8, and the other end of the transmission rod is hinged with the sliding block 26; the sliding block 26 is fixedly connected with the lower ends of the two fingers; the two fingers slide in a disc groove 5 on the palm 4; the two fingers grab and wrap different crops.

The two fingers are three in number, have the same structure and are respectively an index finger 1, a middle finger 2 and a thumb 3; the two fingers comprise an upper finger segment 38 and a lower finger segment 40; the upper finger section 38 is hinged with the lower finger section 40; an elastic plate 42 is fixed on the lower finger section 40; the lower finger section 40 is provided with a rectangular through groove; the finger upper section 38 is provided with a rectangular groove; one end of the finger curved rod 39 passes through the rectangular through groove to be fixedly connected with the elastic plate 42, and the other end of the finger curved rod is connected with the finger upper section 38; the upper finger section 38 is provided with a hinge hole 41; the fingers are inclined inwards; the top of the upper finger segment 38 is curved inwardly.

The index finger 1, middle finger 2 and thumb 3 are symmetrical about a central axis 10; the angle between the middle finger 2 and the thumb 3 is smaller than the angle between the index finger 1 and the middle finger 2 and the angle between the index finger 1 and the thumb 3.

The palm 4 is of a disc structure; three rectangular disc grooves 5 are formed in the palm 4 and respectively comprise a middle finger track 28, an index finger track 31 and a thumb track 32; the middle finger track 28 and the thumb track 32 are symmetrical about the index finger track 31; the middle of the palm 4 is a central palm 29.

The lower end of the sliding block 26 is provided with a lower hinge hole 27, and the upper end is provided with a first plug-in rod 22, a second plug-in rod 23, a third plug-in rod 24 and a fifth plug-in rod 25; the first insertion rod 22, the second insertion rod 23, the third insertion rod 24 and the fifth insertion rod 25 are inserted into holes of the lower finger joint 40, so that the sliding block 26 is fixed with the fingers; the slide block 26 is provided with a through hole; the through hole passes through a shaft provided on the disc groove 5.

The central sleeve 8 comprises a hollow sleeve body 18; three lug plates are arranged on the outer side of the sleeve body 18; the three ear plates are respectively provided with a first lower hinge hole 19, a second lower hinge hole 20 and a third lower hinge hole 21; the central sleeve 8 is hinged with the lower end of the transmission rod 6 through a first lower hinge hole 19, a second lower hinge hole 20 and a third lower hinge hole 21; the upper end of the driving rod 6 is hinged through a lower hinge hole 27.

The transmission rod assembly 9 comprises a first transmission rod 13, a second transmission rod 14 and a third transmission rod 15; the upper ends of the first transmission rod 13, the second transmission rod 14 and the third transmission rod 15 are fixedly connected with the sleeve body 18, and the lower ends of the first transmission rod, the second transmission rod and the third transmission rod are fixedly connected with the piston 11.

One end of the first transmission rod 13, the second transmission rod 14 and the third transmission rod 15 is provided with a transmission rod upper hinge hole 34, and the other end is provided with a transmission rod lower hinge hole 36; the first transmission rod 13, the second transmission rod 14 and the third transmission rod 15 are connected with the central sleeve 8 through transmission rod lower hinge holes 36 and bolts 37; the first transmission rod 13, the second transmission rod 14 and the third transmission rod 15 are connected with the sliding block 26 through the transmission rod hinge holes 34 and the bolts 37.

A pressure sensor is arranged on the elastic plate 42; the pressure sensor is connected with the main controller; the master controller is connected to the hydraulic cylinder 12.

The utility model has the advantages that:

1) The utility model adopts an under-actuated structure, the driving units are few, the energy consumption is low, the structure is corresponding and not complex, the transmission chain is short and compact, the stability is better, the error of the transmission system is reduced to a great extent, the corresponding manufacturing cost is also lower, and simultaneously, the fruit can be grabbed without damage according to the signal transmission of the mechanical sensor to the main controller;

2) The fingers of the utility model are provided with two-section structures, the upper parts of the fingers are bent inwards to wrap fruits in the grabbing process, and the grabbing is firmer due to the design of the whole structure;

3) The utility model discloses a practicality is stronger, can realize snatching the fruit of multiple different shapes, and the particularity of finger in the position of disc central angle has decided its comparatively extensive adaptability.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments will be briefly described below, it should be understood that the following drawings only show some embodiments of the present invention and therefore should not be considered as limiting the scope, and those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

FIG. 1 is a schematic view of the overall construction of the present invention;

fig. 2 is a schematic structural view of the hydraulic cylinder of the present invention;

FIG. 3 is a schematic structural view of the center sleeve of the present invention;

FIG. 4 is a schematic structural view of the slider of the present invention;

FIG. 5 is a schematic view of the structure of the disk structure and the slide block moving guide rail of the present invention;

fig. 6 is a schematic structural view of the transmission rod of the present invention;

fig. 7 is a schematic structural view of the bolt of the present invention;

FIG. 8 is a schematic view of the structure of a finger according to the present invention;

fig. 9 is a schematic top view of a finger according to the present invention.

In the figure:

1. the index finger; 2. middle finger; 3. a thumb; 4. a palm; 5. a disc groove; 6. a transmission rod; 8. a central sleeve; 9. a transmission rod assembly; 10. a central shaft; 11. a piston; 12. a hydraulic cylinder; 13. a first transmission lever; 14. a second transmission rod; 15. a third transmission rod; 16. an output end; 18. a sleeve body; 19. a first lower reaming hole; 20. a second lower reaming hole; 21. a third lower reaming hole; 22. a first insertion rod; 23. a second insertion rod; 24. a third plug-in rod; 25. a fifth plug-in mounting rod; 26. a slider; 27. reaming the hole downwards; 28. a middle finger track; 29. a central palm; 31. an index finger track; 32. a thumb track; 34. reaming the transmission rod; 36. The transmission rod is reamed; 37. a bolt; 38. the upper section of the finger; 39. a finger crank; 40. a lower finger section; 41. Reaming; 42. an elastic plate.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the present application, unless expressly stated or limited otherwise, the recitation of a first feature "on" or "under" a second feature may include the recitation of the first and second features being in direct contact, and may also include the recitation of the first and second features not being in direct contact, but being in contact with another feature between them. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. "beneath," "under" and "beneath" a first feature includes the first feature being directly beneath and obliquely beneath the second feature, or simply indicating that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used in the orientation or positional relationship shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

The two fingers have three same structures and are respectively an index finger 1, a middle finger 2 and a thumb 3; the two sections of fingers comprise an upper finger section 38 and a lower finger section 40; the upper finger section 38 is hinged with the lower finger section 40; an elastic plate 42 is fixed on the lower finger section 40; the lower finger section 40 is provided with a rectangular through groove; the finger upper section 38 is provided with a rectangular groove; one end of the finger curved rod 39 passes through the rectangular through groove to be fixedly connected with the elastic plate 42, and the other end of the finger curved rod is connected with the finger upper section 38; the upper finger section 38 is provided with a hinge hole 41; the fingers are inclined inwards; the top of the upper finger segment 38 is curved inwardly. When picking fruit, the elastic plate 42 firstly contacts with the fruit, and pushes the finger curved rod 39 after the contact, so that the finger upper section 38 rotates around the reaming 41 to wrap the fruit. The structure of the index finger 1, the middle finger 2 and the thumb 3 of the device is completely the same, the middle finger 2 and the thumb 3 are symmetrical about the index finger 1, and in the grabbing process, the movement processes of the three fingers are completely the same, so that the fruit is completely wrapped.

The angle between the middle finger 2 and the thumb 3 is smaller than the angle between the index finger 1 and the middle finger 2 and the index finger 1 and the thumb 3. The central angle of the two fingers with the smaller included angle on the cross section is between 30 and 60 degrees, and the central angle of the other two fingers is between 150 and 165 degrees. Therefore, the fruit with different sizes and shapes can be grabbed.

The palm 4 is of a disc structure; the middle of the palm 4 is a central palm 29.

The middle part of the palm 4 adopts a herringbone structure, and three branches of the herringbone structure are respectively provided with a rectangular guide rail, namely a middle finger rail 28, an index finger rail 31 and a thumb rail 32; the middle finger track 28 and thumb track 32 are symmetrical about the index finger track 31; the middle finger rail 28, the index finger rail 31 and the sliding block 26 on the thumb rail 32 are connected with fingers, and the symmetry of the disc structure is utilized to ensure the high efficiency and accuracy of power transmission and simultaneously lift the picked fruits.

The middle finger track 28, the index finger track 31 and the thumb track 32 correspond to the motion tracks of the middle finger 2, the index finger 1 and the thumb 3; the principle of the utility model is that the grabbing process is realized by controlling the position of the third transmission rod of the finger at the position of the control slider 26 on the track. The symmetry of the palm 4 is good, so that the whole grabbing process is better realized.

The middle finger track 28 and thumb track 32 are symmetrical about the index finger track 31. It will be appreciated that the angle subtended by the thumb track 32 and the index track 31 is the same as the angle subtended by the middle track 28 and the index track 31, but this angle is not equal to the angle subtended by the thumb track 32 and the middle track 28. In the design process, the angle that thumb track 32 and middle finger track 28 pressed from both sides is 30 degrees to 60 degrees, and the angle that thumb track 32 and forefinger track 31 pressed from both sides and the angle that middle finger track 28 and forefinger track 31 pressed from both sides are between 150 degrees to 165 degrees, and the design of this kind of structure makes the utility model discloses both can snatch the fruit of circular shape like the apple, also can snatch the banding fruit of circle like the cucumber for this grabbing device's suitability scope is wider.

The lower end of the sliding block 26 is provided with a lower hinge hole 27, and the upper end is provided with insertion rods, namely a first insertion rod 22, a second insertion rod 23, a third insertion rod 24 and a fifth insertion rod 25; the first insertion rod 22, the second insertion rod 23, the third insertion rod 24 and the fifth insertion rod 25 are inserted into holes of the lower finger section 40, so that the sliding block 26 is fixed with fingers, and the stability and accuracy of movement are guaranteed. The slide block 26 is provided with a through hole; the through hole passes through a shaft provided on the disc groove 5. The slider 26 moves on a shaft on the disc groove 5, thereby moving the finger on the disc groove 5.

The central sleeve 8 comprises a hollow sleeve body 18; the movement of the central sleeve 8 on the central shaft 10 is controlled to control the position of the sliding blocks 26 on the middle finger track 28, the index finger track 31 and the thumb track 32, and the movement is realized by connecting the three hinge holes of the first lower hinge hole 19, the second lower hinge hole 20 and the third lower hinge hole 21 with the lower hinge holes 27 of the three sliding blocks 26, and the hinge holes are connected through bolts 37. The upper hinge hole 34 of the transmission rod and the lower hinge hole 36 of the transmission rod are connected by bolts, thereby realizing the under-actuated structure of the utility model. The utility model discloses only need the central sleeve 8 on the control center axle 10 one prime mover to control the removal on the track of three slider 26. The motion of three driven parts can be controlled by only controlling one driving part, the driving parts are few, and the energy consumption is low. This is the under-actuated structure principle of the utility model similar to the umbrella structure. When the utility model discloses when receiving the order of snatching the fruit, pneumatic cylinder 12 is through promoting first transfer line 13, second transfer line 14, and the three pole of third transfer line 15 and then promote the motion of central sleeve 8 on center pin 10, thereby the opening of controlling slider 23 position on the track and closing the realization and snatch the process.

Three lug plates are arranged on the outer side of the sleeve body 18; the three ear plates are respectively provided with a first lower hinge hole 19, a second lower hinge hole 20 and a third lower hinge hole 21; the central sleeve 8 is hinged with the lower end of the transmission rod 6 through a first lower hinge hole 19, a second lower hinge hole 20 and a third lower hinge hole 21; the upper end of the transmission rod 6 is hinged through a lower hinge hole 27.

The transmission rod assembly 9 comprises a first transmission rod 13, a second transmission rod 14 and a third transmission rod 15; the upper ends of the first transmission rod 13, the second transmission rod 14 and the third transmission rod 15 are fixedly connected with the sleeve body 18, and the lower ends are fixedly connected with the piston 11.

One end of the first transmission rod 13, the second transmission rod 14 and the third transmission rod 15 is provided with a transmission rod upper hinge hole 34, and the other end is provided with a transmission rod lower hinge hole 36; the first transmission rod 13, the second transmission rod 14 and the third transmission rod 15 are connected with the central sleeve 8 through the transmission rod lower hinge hole 36 and the bolt 37; the first transmission rod 13, the second transmission rod 14 and the third transmission rod 15 are connected with the sliding block 26 through the transmission rod hinge holes 34 and the bolts 37.

Pneumatic cylinder 12 comes control piston 11's flexible through the volume of control oil feed and oil production, and then controls the flexible of first transfer line 13, second transfer line 14 and third transfer line 15 to come the motion of control center sleeve 8 on center pin 10, the utility model discloses a motion ring is detained mutually, only needs the motion amount of control pneumatic cylinder 12 can control snatching of last finger, and simple structure understands, and motion simple structure and compactness.

After inputting the actuating signal, pneumatic cylinder 12 promotes the push rod upward movement, finally realizes snatching of fruit, at the in-process of snatching the fruit, we control through the mechanics sensor on the elastic plate 42 the utility model discloses a stop. When the grabbing process is finished, the movement of the hydraulic cylinder 12 is also controlled to finally realize the resetting of the slide block 25 and the fingers.

The utility model discloses a theory of operation does:

before the operation, the fingers are in the initial state, the starting signal is input, the hydraulic cylinder 12 starts to operate, the hydraulic cylinder pushes the transmission rod assembly 9 to move upwards through the control piston 11, and the transmission rod assembly 9 pushes the central sleeve 8 to move upwards on the central shaft 10. Correspondingly, the central sleeve 7 is connected to the sliding blocks 26 by means of the hinge holes in it, the connection of the two hinge holes being effected by means of the driving rods 6, which in turn control the movement of the three sliding blocks 26 on the respective tracks. This is the motion principle of whole grabbing device, just can control the motion of three slider 26 through the motion of control pneumatic cylinder 12, and the motion of these three slider 26 is complete symmetry, very dexterous control the utility model discloses a motion structure.

In the grabbing process, as the sliding block 26 drives the forefinger 1, the middle finger 2 and the thumb 3 to move, when the fingers contact with the fruits, the elastic plate 42 protrudes outwards, so that the elastic plate 42 always contacts with the fruits firstly, and after the fruits are contacted, the elastic plate 42 contracts inwards, so that the finger bent rod 39 pushes the upper sections of the fingers to bend inwards through the hinge holes 41 to wrap the fruits. Because 3 fingers are the same completely, thereby it all is in the common parcel of the corresponding same position of guide rail and live the fruit, and then realizes snatching the process. Since the elastic plate is made of a correspondingly flexible material, the fruit is influenced only slightly during the gripping process. At the same time, at the position of the elastic plate 42, a mechanical sensor is added, which is connected to the termination signal terminal. When the force reaches the corresponding preset value in the grabbing process, the corresponding hydraulic cylinder is controlled to stop moving, the picking of the fruits is achieved, and the task of the whole device is completed.

After the grabbing process is finished, inputting a corresponding reset signal, and then finishing the corresponding reset process. After the fruit is picked, the elastic plate 42 does not contact with the fruit, and no corresponding force is applied to make the finger curved rod 39 pull the upper segment of the finger back to the original position, so that the finger returns to the original position. At the same time the piston 11 of the hydraulic cylinder 12 moves downwards, which causes the centre sleeve 8 on the centre shaft 10 to move downwards, because the transmission rod 6 and the centre sleeve 8 are fastened together. Similar to the starting process, because the hinge hole on the central sleeve 8 is connected with the hinge hole on the sliding block 26 through the transmission rod 6, the downward movement of the central sleeve 8 enables the sliding block 26 on the disk to move outwards and finally return to the original position, and the reset of the whole utility model is realized.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, however, the protection scope of the present invention is not limited to the details of the above embodiments, and within the technical concept of the present invention, any person skilled in the art is within the technical scope of the present invention, and according to the technical solution of the present invention and the inventive concept thereof, equivalent replacement or change is made, and these simple modifications all belong to the protection scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and in order to avoid unnecessary repetition, the present invention does not separately describe various possible combinations.

In addition, various embodiments of the present invention can be arbitrarily combined with each other, and the disclosed content of the present invention should be considered as the same as long as it does not violate the idea of the present invention.

Claims

1. An under-actuated mechanical hand device is characterized by comprising a palm (4), two fingers, a transmission rod (6), a central sleeve (8), a transmission rod assembly (9), a central shaft (10) and a hydraulic cylinder (12); a piston (11) of an output end (16) of the hydraulic cylinder (12) is fixedly connected with one end of the transmission rod assembly (9); the other end of the transmission rod assembly (9) is fixedly connected with the central sleeve (8); the central sleeve (8) is sleeved on the central shaft (10); the upper end of the central shaft is fixedly connected with a palm (4); the palm (4) is fixedly connected with the hydraulic cylinder (12) through a connecting piece; one end of the transmission rod (6) is hinged with the central sleeve (8), and the other end of the transmission rod is hinged with the sliding block (26); the sliding block (26) is fixedly connected with the lower ends of the two fingers; the two fingers slide in a disc groove (5) on the palm (4); the two fingers grab and wrap different crops.

2. An under-actuated manipulator device as claimed in claim 1, wherein the two fingers have three identical structures, namely, an index finger (1), a middle finger (2) and a thumb (3); the two sections of fingers comprise an upper finger section (38) and a lower finger section (40); the upper finger segment (38) is hinged with the lower finger segment (40); an elastic plate (42) is fixed on the lower finger section (40); the lower finger section (40) is provided with a rectangular through groove; the finger upper section (38) is provided with a rectangular groove; one end of the finger curved rod (39) penetrates through the rectangular through groove to be fixedly connected with the elastic plate (42), and the other end of the finger curved rod is connected with the finger upper section (38); the upper finger section (38) is provided with a hinge hole (41); the fingers are inclined inwards; the top of the upper finger knuckle (38) is curved inward.

3. An under-actuated manipulator device according to claim 2, wherein the index finger (1), middle finger (2) and thumb (3) are symmetrical about a central axis (10); the angle between the middle finger (2) and the thumb (3) is smaller than the angle between the index finger (1) and the middle finger (2) and the angle between the index finger (1) and the thumb (3).

4. An under-actuated manipulator device according to claim 1, wherein the palm (4) is of a disc structure; three rectangular disc grooves (5) are formed in the palm (4) and respectively comprise a middle finger track (28), an index finger track (31) and a thumb track (32); the middle finger track (28) and the thumb track (32) are symmetrical with respect to the index finger track (31); the middle of the palm (4) is a central palm (29).

5. An under-actuated manipulator device as claimed in claim 2, wherein the lower end of the slide block (26) is provided with a lower hinge hole (27), and the upper end is provided with insertion rods, namely a first insertion rod (22), a second insertion rod (23), a third insertion rod (24) and a fifth insertion rod (25); the first insertion rod (22), the second insertion rod (23), the third insertion rod (24) and the fifth insertion rod (25) are inserted into holes of a lower finger section (40), so that the sliding block (26) is fixed with the fingers; the sliding block (26) is provided with a through hole; the through hole passes through a shaft arranged on the disc groove (5).

6. An under-actuated manipulator device according to claim 5, wherein said central sleeve (8) comprises a hollow sleeve body (18); three ear plates are arranged on the outer side of the sleeve body (18); the three ear plates are respectively provided with a first lower hinge hole (19), a second lower hinge hole (20) and a third lower hinge hole (21); the central sleeve (8) is hinged with the lower end of the transmission rod (6) through a first lower hinge hole (19), a second lower hinge hole (20) and a third lower hinge hole (21); the upper end of the transmission rod (6) is hinged through a lower hinge hole (27).

7. An under-actuated manipulator arrangement according to claim 6, wherein the transmission rod assembly (9) comprises a first transmission rod (13), a second transmission rod (14) and a third transmission rod (15); the upper ends of the first transmission rod (13), the second transmission rod (14) and the third transmission rod (15) are fixedly connected with the sleeve body (18), and the lower ends of the first transmission rod, the second transmission rod and the third transmission rod are fixedly connected with the piston (11).

8. An under-actuated manipulator device according to claim 7, wherein the first, second and third transmission rods (13, 14, 15) are provided with an upper transmission rod hinge hole (34) at one end and a lower transmission rod hinge hole (36) at the other end; the first transmission rod (13), the second transmission rod (14) and the third transmission rod (15) are connected with the central sleeve (8) through transmission rod lower hinge holes (36) and bolts (37); the first transmission rod (13), the second transmission rod (14) and the third transmission rod (15) are connected with the sliding block (26) through hinge holes (34) and bolts (37) in the transmission rods.

9. An under-actuated manipulator device according to claim 3, wherein said elastic plate (42) is provided with a pressure sensor; the pressure sensor is connected with the main controller; the main controller is connected with the hydraulic cylinder (12).